proc.c

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/*
 *  proc.c
 *
 *  Copyright (C) 1995, 1996 by Paal-Kr. Engstad and Volker Lendecke
 *
 *  28/06/96 - Fixed long file name support (smb_proc_readdir_long) by Yuri Per
 */

#include <linux/config.h>
#include <linux/fs.h>
#include <linux/smbno.h>
#include <linux/smb_fs.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/malloc.h>
#include <linux/stat.h>
#include <linux/fcntl.h>
#include <asm/segment.h>
#include <asm/string.h>

#define SMB_VWV(packet)  ((packet) + SMB_HEADER_LEN)
#define SMB_CMD(packet)  (BVAL(packet,8))
#define SMB_WCT(packet)  (BVAL(packet, SMB_HEADER_LEN - 1))
#define SMB_BCC(packet)  smb_bcc(packet)
#define SMB_BUF(packet)  ((packet) + SMB_HEADER_LEN + SMB_WCT(packet) * 2 + 2)

#define SMB_DIRINFO_SIZE 43
#define SMB_STATUS_SIZE  21

static int smb_request_ok(struct smb_server *s, int command, int wct, int bcc);

static inline int
min(int a, int b)
{
	return a < b ? a : b;
}

static void
str_upper(char *name)
{
	while (*name)
	{
		if (*name >= 'a' && *name <= 'z')
			*name -= ('a' - 'A');
		name++;
	}
}

static void
str_lower(char *name)
{
	while (*name)
	{
		if (*name >= 'A' && *name <= 'Z')
			*name += ('a' - 'A');
		name++;
	}
}

/*****************************************************************************/
/*                                                                           */
/*  Encoding/Decoding section                                                */
/*                                                                           */
/*****************************************************************************/

static inline byte *
smb_decode_word(byte * p, word * data)
{
	*data = WVAL(p, 0);
	return p + 2;
}

byte *
smb_encode_smb_length(byte * p, dword len)
{
	BSET(p, 0, 0);
	BSET(p, 1, 0);
	BSET(p, 2, (len & 0xFF00) >> 8);
	BSET(p, 3, (len & 0xFF));
	if (len > 0xFFFF)
	{
		BSET(p, 1, 1);
	}
	return p + 4;
}

static byte *
smb_encode_ascii(byte * p, const byte * name, int len)
{
	*p++ = 4;
	strcpy(p, name);
	return p + len + 1;
}

static byte *
smb_encode_this_name(byte * p, const char *name, const int len)
{
	*p++ = '\\';
	strncpy(p, name, len);
	return p + len;
}

/* I put smb_encode_parents into a separate function so that the
   recursion only takes 16 bytes on the stack per path component on a
   386. */

static byte *
smb_encode_parents(byte * p, struct smb_inode_info *ino)
{
	byte *q;

	if (ino->dir == NULL)
	{
		return p;
	}
	q = smb_encode_parents(p, ino->dir);
	if (q - p + 1 + ino->finfo.len > SMB_MAXPATHLEN)
	{
		return p;
	}
	return smb_encode_this_name(q, ino->finfo.name, ino->finfo.len);
}

static byte *
smb_encode_path(struct smb_server *server,
		byte * p, struct smb_inode_info *dir,
		const char *name, const int len)
{
	byte *start = p;
	if (dir != NULL)
	{
		p = smb_encode_parents(p, dir);
	}
	p = smb_encode_this_name(p, name, len);
	*p++ = 0;
	if (server->protocol <= PROTOCOL_COREPLUS)
	{
		str_upper(start);
	}
	return p;
}

static byte *
smb_decode_data(byte * p, byte * data, word * data_len, int fs)
{
	word len;

	if (!(*p == 1 || *p == 5))
	{
		printk("smb_decode_data: Warning! Data block not starting "
		       "with 1 or 5\n");
	}
	len = WVAL(p, 1);
	p += 3;

	if (fs)
		memcpy_tofs(data, p, len);
	else
		memcpy(data, p, len);

	*data_len = len;

	return p + len;
}

static byte *
smb_name_mangle(byte * p, const byte * name)
{
	int len, pad = 0;

	len = strlen(name);

	if (len < 16)
		pad = 16 - len;

	*p++ = 2 * (len + pad);

	while (*name)
	{
		*p++ = (*name >> 4) + 'A';
		*p++ = (*name & 0x0F) + 'A';
		name++;
	}
	while (pad--)
	{
		*p++ = 'C';
		*p++ = 'A';
	}
	*p++ = '\0';

	return p;
}

/* The following are taken directly from msdos-fs */

/* Linear day numbers of the respective 1sts in non-leap years. */

static int day_n[] =
{0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 0, 0, 0, 0};
		  /* JanFebMarApr May Jun Jul Aug Sep Oct Nov Dec */


extern struct timezone sys_tz;

static int
utc2local(int time)
{
	return time - sys_tz.tz_minuteswest * 60;
}

static int
local2utc(int time)
{
	return time + sys_tz.tz_minuteswest * 60;
}

/* Convert a MS-DOS time/date pair to a UNIX date (seconds since 1 1 70). */

static int
date_dos2unix(unsigned short time, unsigned short date)
{
	int month, year, secs;

	month = ((date >> 5) & 15) - 1;
	year = date >> 9;
	secs = (time & 31) * 2 + 60 * ((time >> 5) & 63) + (time >> 11) * 3600 + 86400 *
	    ((date & 31) - 1 + day_n[month] + (year / 4) + year * 365 - ((year & 3) == 0 &&
						   month < 2 ? 1 : 0) + 3653);
	/* days since 1.1.70 plus 80's leap day */
	return local2utc(secs);
}

/*****************************************************************************/
/*                                                                           */
/*  Support section.                                                         */
/*                                                                           */
/*****************************************************************************/

dword
smb_len(byte * p)
{
	return ((BVAL(p, 1) & 0x1) << 16L) | (BVAL(p, 2) << 8L) | (BVAL(p, 3));
}

static word
smb_bcc(byte * packet)
{
	int pos = SMB_HEADER_LEN + SMB_WCT(packet) * sizeof(word);
	return WVAL(packet, pos);
}

/* smb_valid_packet: We check if packet fulfills the basic
   requirements of a smb packet */

static int
smb_valid_packet(byte * packet)
{
	DDPRINTK("len: %d, wct: %d, bcc: %d\n",
		 smb_len(packet), SMB_WCT(packet), SMB_BCC(packet));
	return (packet[4] == 0xff
		&& packet[5] == 'S'
		&& packet[6] == 'M'
		&& packet[7] == 'B'
		&& (smb_len(packet) + 4 == SMB_HEADER_LEN
		    + SMB_WCT(packet) * 2 + SMB_BCC(packet)));
}

/* smb_verify: We check if we got the answer we expected, and if we
   got enough data. If bcc == -1, we don't care. */

static int
smb_verify(byte * packet, int command, int wct, int bcc)
{
	return (SMB_CMD(packet) == command &&
		SMB_WCT(packet) >= wct &&
		(bcc == -1 || SMB_BCC(packet) >= bcc)) ? 0 : -EIO;
}

static int
smb_errno(int errcls, int error)
{
	if (errcls == ERRDOS)
		switch (error)
		{
		case ERRbadfunc:
			return EINVAL;
		case ERRbadfile:
			return ENOENT;
		case ERRbadpath:
			return ENOENT;
		case ERRnofids:
			return EMFILE;
		case ERRnoaccess:
			return EACCES;
		case ERRbadfid:
			return EBADF;
		case ERRbadmcb:
			return EREMOTEIO;
		case ERRnomem:
			return ENOMEM;
		case ERRbadmem:
			return EFAULT;
		case ERRbadenv:
			return EREMOTEIO;
		case ERRbadformat:
			return EREMOTEIO;
		case ERRbadaccess:
			return EACCES;
		case ERRbaddata:
			return E2BIG;
		case ERRbaddrive:
			return ENXIO;
		case ERRremcd:
			return EREMOTEIO;
		case ERRdiffdevice:
			return EXDEV;
		case ERRnofiles:
			return 0;
		case ERRbadshare:
			return ETXTBSY;
		case ERRlock:
			return EDEADLK;
		case ERRfilexists:
			return EEXIST;
		case 87:
			return 0;	/* Unknown error!! */
			/* This next error seems to occur on an mv when
			 * the destination exists */
		case 183:
			return EEXIST;
		default:
			return EIO;
	} else if (errcls == ERRSRV)
		switch (error)
		{
		case ERRerror:
			return ENFILE;
		case ERRbadpw:
			return EINVAL;
		case ERRbadtype:
			return EIO;
		case ERRaccess:
			return EACCES;
		default:
			return EIO;
	} else if (errcls == ERRHRD)
		switch (error)
		{
		case ERRnowrite:
			return EROFS;
		case ERRbadunit:
			return ENODEV;
		case ERRnotready:
			return EUCLEAN;
		case ERRbadcmd:
			return EIO;
		case ERRdata:
			return EIO;
		case ERRbadreq:
			return ERANGE;
		case ERRbadshare:
			return ETXTBSY;
		case ERRlock:
			return EDEADLK;
		default:
			return EIO;
	} else if (errcls == ERRCMD)
		return EIO;
	return 0;
}

static void
smb_lock_server(struct smb_server *server)
{
	while (server->lock)
		sleep_on(&server->wait);
	server->lock = 1;
}

static void
smb_unlock_server(struct smb_server *server)
{
	if (server->lock != 1)
	{
		printk("smb_unlock_server: was not locked!\n");
	}
	server->lock = 0;
	wake_up(&server->wait);
}

/* smb_request_ok: We expect the server to be locked. Then we do the
   request and check the answer completely. When smb_request_ok
   returns 0, you can be quite sure that everything went well. When
   the answer is <=0, the returned number is a valid unix errno. */

static int
smb_request_ok(struct smb_server *s, int command, int wct, int bcc)
{
	int result = 0;
	s->rcls = 0;
	s->err = 0;

	if (smb_request(s) < 0)
	{
		DPRINTK("smb_request failed\n");
		result = -EIO;
	} else if (smb_valid_packet(s->packet) != 0)
	{
		DPRINTK("not a valid packet!\n");
		result = -EIO;
	} else if (s->rcls != 0)
	{
		result = -smb_errno(s->rcls, s->err);
	} else if (smb_verify(s->packet, command, wct, bcc) != 0)
	{
		DPRINTK("smb_verify failed\n");
		result = -EIO;
	}
	return result;
}

/* smb_retry: This function should be called when smb_request_ok has
   indicated an error. If the error was indicated because the
   connection was killed, we try to reconnect. If smb_retry returns 0,
   the error was indicated for another reason, so a retry would not be
   of any use. */

static int
smb_retry(struct smb_server *server)
{
	if (server->state != CONN_INVALID)
	{
		return 0;
	}
	if (smb_release(server) < 0)
	{
		DPRINTK("smb_retry: smb_release failed\n");
		server->state = CONN_RETRIED;
		return 0;
	}
	if (smb_proc_reconnect(server) < 0)
	{
		DPRINTK("smb_proc_reconnect failed\n");
		server->state = CONN_RETRIED;
		return 0;
	}
	server->state = CONN_VALID;
	return 1;
}

static int
smb_request_ok_unlock(struct smb_server *s, int command, int wct, int bcc)
{
	int result = smb_request_ok(s, command, wct, bcc);

	smb_unlock_server(s);

	return result;
}

/* smb_setup_header: We completely set up the packet. You only have to
   insert the command-specific fields */

__u8 *
smb_setup_header(struct smb_server * server, byte command, word wct, word bcc)
{
	dword xmit_len = SMB_HEADER_LEN + wct * sizeof(word) + bcc + 2;
	byte *p = server->packet;
	byte *buf = server->packet;

	p = smb_encode_smb_length(p, xmit_len - 4);

	BSET(p, 0, 0xff);
	BSET(p, 1, 'S');
	BSET(p, 2, 'M');
	BSET(p, 3, 'B');
	BSET(p, 4, command);

	p += 5;
	memset(p, '\0', 19);
	p += 19;
	p += 8;

	WSET(buf, smb_tid, server->tid);
	WSET(buf, smb_pid, server->pid);
	WSET(buf, smb_uid, server->server_uid);
	WSET(buf, smb_mid, server->mid);

	if (server->protocol > PROTOCOL_CORE)
	{
		BSET(buf, smb_flg, 0x8);
		WSET(buf, smb_flg2, 0x3);
	}
	*p++ = wct;		/* wct */
	p += 2 * wct;
	WSET(p, 0, bcc);
	return p + 2;
}

/* smb_setup_header_exclusive waits on server->lock and locks the
   server, when it's free. You have to unlock it manually when you're
   finished with server->packet! */

static byte *
smb_setup_header_exclusive(struct smb_server *server,
			   byte command, word wct, word bcc)
{
	smb_lock_server(server);
	return smb_setup_header(server, command, wct, bcc);
}

static void
smb_setup_bcc(struct smb_server *server, byte * p)
{
	__u8 *packet = server->packet;
	__u8 *pbcc = packet + SMB_HEADER_LEN + 2 * SMB_WCT(packet);
	__u16 bcc = p - (pbcc + 2);

	WSET(pbcc, 0, bcc);
	smb_encode_smb_length(packet,
			      SMB_HEADER_LEN + 2 * SMB_WCT(packet) - 2 + bcc);
}


/*****************************************************************************/
/*                                                                           */
/*  File operation section.                                                  */
/*                                                                           */
/*****************************************************************************/

int
smb_proc_open(struct smb_server *server,
	      struct smb_inode_info *dir, const char *name, int len,
	      struct smb_dirent *entry)
{
	int error;
	char *p;
	char *buf;
	const word o_attr = aSYSTEM | aHIDDEN | aDIR;

	DPRINTK("smb_proc_open: name=%s\n", name);

	smb_lock_server(server);

	if (entry->opened != 0)
	{
		/* Somebody else opened the file while we slept */
		smb_unlock_server(server);
		return 0;
	}
      retry:
	buf = server->packet;
	p = smb_setup_header(server, SMBopen, 2, 0);
	WSET(buf, smb_vwv0, 0x42);	/* read/write */
	WSET(buf, smb_vwv1, o_attr);
	*p++ = 4;
	p = smb_encode_path(server, p, dir, name, len);
	smb_setup_bcc(server, p);

	if ((error = smb_request_ok(server, SMBopen, 7, 0)) != 0)
	{

		if (smb_retry(server))
		{
			goto retry;
		}
		if ((error != -EACCES) && (error != -ETXTBSY)
		    && (error != -EROFS))
		{
			smb_unlock_server(server);
			return error;
		}
		/* N.B. Packet may change after request */
		buf = server->packet;
		p = smb_setup_header(server, SMBopen, 2, 0);
		WSET(buf, smb_vwv0, 0x40);	/* read only */
		WSET(buf, smb_vwv1, o_attr);
		*p++ = 4;
		p = smb_encode_path(server, p, dir, name, len);
		smb_setup_bcc(server, p);

		if ((error = smb_request_ok(server, SMBopen, 7, 0)) != 0)
		{
			if (smb_retry(server))
			{
				goto retry;
			}
			smb_unlock_server(server);
			return error;
		}
	}
	/* We should now have data in vwv[0..6]. */

	/* N.B. Packet may change after request */
	buf = server->packet;
	entry->fileid = WVAL(buf, smb_vwv0);
	entry->attr = WVAL(buf, smb_vwv1);
	entry->f_ctime = entry->f_atime =
	    entry->f_mtime = local2utc(DVAL(buf, smb_vwv2));
	entry->f_size = DVAL(buf, smb_vwv4);
	entry->access = WVAL(buf, smb_vwv6);

	entry->opened = 1;
	entry->access &= 3;

	smb_unlock_server(server);

	DPRINTK("smb_proc_open: entry->access = %d\n", entry->access);
	return 0;
}

int
smb_proc_close(struct smb_server *server,
	       __u16 fileid, __u32 mtime)
{
	char *buf;

	smb_setup_header_exclusive(server, SMBclose, 3, 0);
	buf = server->packet;
	WSET(buf, smb_vwv0, fileid);
	DSET(buf, smb_vwv1, utc2local(mtime));

	return smb_request_ok_unlock(server, SMBclose, 0, 0);
}

/* In smb_proc_read and smb_proc_write we do not retry, because the
   file-id would not be valid after a reconnection. */

/* smb_proc_read: fs indicates if it should be copied with
   memcpy_tofs. */

int
smb_proc_read(struct smb_server *server, struct smb_dirent *finfo,
	      off_t offset, long count, char *data, int fs)
{
	word returned_count, data_len;
	char *buf;
	int error;